Open Water

What lurks beneath

Swimming with jellyfish

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“I’m not screaming every time… just at the really big ones,” my wife Mara shouted over to me while bobbing in the waters of Shinnecock Bay in eastern Long Island during a 1.7-mile training swim. As if she had to defend her toughness to me. She most certainly didn’t.

I was in my usual position, with the kayak's thick yellow plastic shielding me from the hundreds or thousands of jellyfish of various sizes just below the surface. I often accompany Mara on her training swims, a task which we view as fair given her tireless support for my marathons. Mara can’t run because of a back problem, but at least in swimming we can spend time together while she trains.

About half a dozen times on this swim, Mara had thrashed her arms and let out a quick, high pitched noise – not so much a scream, as in Freddie Kruger is after me, but more of a screech, as in I just touched something really gross. At first I had thought it was another clump of seaweed, something else Mara had been dealing with on this sunny mid-summer morning. When she told me about the jellyfish invasion, I worried that she would get stung, leading to a cramp and that I would somehow have to help her out of the water and onto the unstable craft. I had an awful vision of her slung over the kayak with hives or shortness of breath. Who knows what those creatures do!

I asked Mara if she wanted to turn around or get in the kayak, but she looked kind of surprised at my question and shook her head no. I would have been out of the water as fast as possible. We distance runners can count ourselves lucky; occasionally we happen upon a rodent, or maybe road kill. We can be chased by dogs or intimidated by SUVs. But rarely, if ever, does a member of another species actually touch us during our workouts. Least of all squishy invertebrates with tentacles.

There have been reports lately of jellyfish populations being on the rise, with everything from global warming to overfishing of the jellies’ larger predators cited as causes. From what I’ve read, there is little proof, partly because it is so hard to count the translucent buggers. However, it seems to be generally accepted that warm weather causes certain types of jellyfish to arrive earlier and in greater abundance. And it has been unusually hot this year in the Northeast U.S.

In 2008, jellyfish fears spiked after a 32-year-old Argentine man died during the New York City Triathlon. Jellies were swarming in the Hudson River that day, and some people suspected that he was stung multiple times, leading to a heart attack. But a coroner later concluded that his death was caused by high blood pressure.

So what exactly are we afraid of? Jellyfish have no bones, brains, circulatory or respiratory systems. They don’t even have a digestive system, just a central cavity that holds plankton or whatever and … well, let’s move on. What they do have are tentacles, and venomous cells that can be used to sting their prey, predators, or even open-water swimmers and surfers. Reactions can vary greatly depending on the jellyfish, and can even cause death in rare cases. The most dangerous type of jellyfish, known as a box jelly, is mostly found in northern Australia or other tropical waters. It’s not a big fan of the Hamptons.

Thankfully, Mara wasn’t stung once on her swim. Just harassed. Maybe even though they lack brains, they respected her need to train for next weekend’s 1.7-miler near Newport, R.I., her longest open-water swim race to date. The Save the Bay Swim raises money to help protect the Narragansett Bay estuary, which according to the race web site is home to more than 60 species of fish and shellfish – including, of course, jellyfish.